In a storage array device, it is not possible to access RAID consisting of disks in the same drive enclosure (DE) when, for example, a power failure occurs in the DE. In order to prevent this, in a storage array device, for example, RAID is configured across multiple DEs.
When new RAID is configured, the storage array device can be configured arbitrarily such that the RAID extend across multiple DEs. However, when the RAID configuration is changed after the operations start, the storage array device mounts a new disk on a destination to which the position of a disk of the RAID configuration is shifted and then performs processing of transferring data from the original disk to the new disk (logical device expansion).
Patent Document 1: Japanese Laid-open Patent Publication No. 2004-54806
Patent Document 2: Japanese Laid-open Patent Publication No. 2006-221526
However, changing the position of a disk of a RAID configuration has a problem in that the changing takes time in proportion to the data capacity of the disk to be shifted. In other words, in the conventional technology, after a new disk is mounted to a new destination to which the position is changed, the storage array device performs processing of transferring data from the original disk to the new disk, which takes time in proportion to the data capacity of the original disk.
The above-described problem occurs also in a case where the configuration is changed such that RAID extends across multiple DEs.